1. Field of the Invention
The present invention relates to the detection of the presence of blood pooling or blood flow within the body and within the head, and more specifically, it relates to the diagnosis of stroke.
2. Description of Related Art
The are two forms of stroke: hemorrhagic and ischemic. Hemorrhagic stroke is caused by internal bleeding within the brain. Ischemic stroke is caused by blockage of a blood vessel that feeds the brain or a region of the brain. A stroke attack can occur suddenly and with little or no warning, and can result in severe physical impairment or death. Due to the rapid timescale for potentially severe or fatal damage to the brain these must be treated as rapidly as possible. Surgical intervention can be used to treat hemorrhagic stroke. An anti-clotting agent can be used to treat ischemic stroke. Unfortunately applying an anticlotting agent in the case of hemorrhagic stroke can cause fatal internal bleeding within the brain. At present, there is no non-invasive way to check patients for, and to differentiate between hemorrhagic and ischemic stroke other than computed tomography (CT) and magnetic resonance imaging (MRI).
The cost of computed tomography and magnetic resonance imaging is high. A typical head scan is about $500–$800, and can cost much more if the patient must be sedated or closely monitored during the scan. In many cases, several scans of a single patient are necessary to monitor the development of his/her condition.
The total time required for a scan is about 15 minutes using a helical scan device (faster than the standard CT scanners). If the scanner is physically located right in the emergency room, this time can go down to 5–10 minutes. However, the actual time to diagnose a brain hemorrhage (or other problem) is usually limited by patient transportation, preparation and the need to have a radiologist read the scan. If the scan must be sent out of the emergency room for reading, the overall time can be between 30 minutes and 3 hours.